This invention relates generally to an apparatus for retrieving a pipe from a well. More particularly, the apparatus is adapted for retrieval of a pipe segment used for testing soil for leakage of oil from underground storage. Such testing might typically occur at a depth of approximately 50 feet.
Pipe segments occasionally become detached in the process of being installed in a well. This is problematic not only because the segment itself is lost at the well bottom, but also because the lost segment blocks the well, making the well useless and requiring redrilling in a separate location. It is therefore desirable to have a tool for retrieving such segments.
Prior patents, such as U.S. Pat. Nos. 3,944,273 and 4,254,983, involve specialized retrieval tools. These tools are designed to retrieve specific objects, and these objects are designed with retrieval in mind. Lacking from the prior art is a device which can attach to any ordinary inner-threaded pipe, within a range of pipe diameters. Such a device is desirable, since many pipes which fall into wells are not specifically designed to couple to a specialized retrieval tool.